Traditional pathology makes use of ex-vivo analysed tissue samples. As a result some of the relevant information of the in-vivo tissue state, e.g. its metabolic state, is lost in this process and cannot be measured on the tissue slide used for histopathology diagnostics. Biopsies are typically performed by surgeons or interventional radiologists, and subsequently examined by a pathologist. An exemplary workflow for obtaining a biopsy is depicted in FIG. 1. For positioning the biopsy device (usually a needle with a shaft 100 having a lateral recess 200, and an outer tubular member 500) accurately in the suspicious tissue, the correct location is commonly determined using image guidance such as Ultrasound or X-ray. While imaging may provide coarse guidance of the needle towards the region of interest, it is often challenging to precisely identify the boundaries of small lesions or tumors with the biopsy needle using standard imaging modalities. As a consequence, biopsies are often taken at the wrong location, which increases the risk of false diagnoses. An additional challenge is the heterogeneity present in many tumors where for example multiple biopsies in different regions of the tumor are required, and this requires more accurate positioning in different parts of the tumor tissue. The association between biopsy location and subsequent biopsy histopathology analysis is important to assess the heterogeneity and the optimal (targeted) therapy to choose. This is becoming more important with the increasing use of neoadjuvant cancer therapy, prior to surgery, e.g. in breast cancer.
There are various imaging devices that provide in-vivo information such as functional MRI imaging and PET-CT imaging. Due to the above described difficulties, it is difficult to link information obtained by these imaging modalities to histopathology results from a biopsy slide taken from the body because the link to the exact position of the biopsy is difficult, in part because of limited resolution of the imaging modalities.
In order to position a biopsy needle under image guidance more accurately in the suspicious tissue, tissue sensing at the tip of the device may be required. Current biopsy needles often do not have such tissue feedback possibilities. Recently, elongated interventional devices have been reported with optical fibers integrated into the device which provide feedback from the tissue at the tip of the device. Such devices allow for fine-guidance towards small volumes of suspicious tissue, in particular for tissue which does not show sufficient contrast in imaging. In order to allow tissue discrimination, these devices employ diffuse reflectance spectroscopy (DRS). For DRS, such devices should be designed with the maximum possible distance between the source and detector fibers to ensure an optimal tissue characterization.